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Discussion Starter #1
Hey guys,
I took my carbs off for cleaning as it was sitting for over a year and bike wouldn’t start.
One things that bothers me is that there are total of 4 shins under needles, is t this a lot? I tried looking to see what jet sizes are in it but numbers are so tiny that I can’t see what they are.
Bike ran fine when it did, started fine when cold and hot, pulled like a train throughout the range.
All is stock, air box (not drilled), snorkel, etc. It lonly has TORs

Any advice appreciated

Thank you
Sasha
 

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Seems like a lot to me. With stock jetting and no mods and the fuel screws set properly there should be no reason to have that many shims IMO
 

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yeah, what he said. Do you have the stock air cleaner in place? If so, no shims should be used. If not, maybe one or 2 at the most. Between about 1/4 and 3/4 throttle the needle is metering based on airflow. The carb is operating in Constant Velocity mode and most modifications don't upset that function.
 

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Discussion Starter #4
Just checked jets and they are stock, 38/98. Stock filter element, air box not drilled, snorkel. The only non stock item are the TORS.
I bought this bike several years ago wit leaky carbs which I fixed but never payed attention to needle and jets. Bike ran fine always, it’s really urgent of the line! But, sometimes and I think only when idles for a while such as at a stop light, when I wanna take off, bike would stall with tiny movement of the throttle. If it’s just quick stop and go, it was fine.
I think it’s probably running too rich on idle with 4 shims.
What do you guys think?
Thanks
Sasha
 

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I would agree it is probably too rich at idle with all those shims. Most will say that the emulsion tube and needle will not draw fuel at idle but I have worked on a bike with worn emulsion tubes (mimicking what you may have going on) that created a very rich mixture at idle and was a real head scratcher trying to figure out why the bike needed the air screws set far out of stock adjustment. Replaced the emulsion tubes and had to go back to stock air screw setting.

What are the fuel screws set at, how many turns out? 2 1/2 is a good starting point.
 

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Discussion Starter #6 (Edited)
They were at 2 1/4. Bike only has about 10k miles so I doubt that emulsion tubes are worn out.
My thinking is that I should assemble it back the way it was. Ride it to see the way it runs and if it still stalls, take few shims off and try again. And hope to learn something that way


Thank you
Sasha
 

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Discussion Starter #7 (Edited)
I do have another question.
Triumph seem to have used every single type of screws/bolts on this bike.
Snorkel clamps have flat head, carb boots on the head Allen in the outside and Phillips on the middle carb. Boot clamps between carbs and airbox has philllips head screws. Taking all the plastics to get to the carbs I had Allen, torx, Phillips, WTH! Are they all like this or just mine?
 

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Well a PO had been in there before so it’s likely they replaced fasteners for some reason. Personally I would replace all the bolts with the same or as close to the same as possible. Hex head bolts work great.

You have Keihin carbs correct? If so they will not suffer emulsion tube wear like the Mikuni carbs will. :)
 

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Discussion Starter #11
I will check needles but how do i know if they are stock? Second, forum here suggests that it's beneficial to up jets to 40/105, should i do this?
What screw heads are supposed to be on the carb to head insulator clamps and on the snorkel clamps? My friends 98 has flat head ones on the head and allen on the snorkel.
Other hardware screws: Metal side covers have allen bolt, carb chrome and black plastic trim pieces have torx and air box/snorkel screws under the seat are torx i think

Thanks
Sasha
 

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The needles should have a number on them near the top.

40 pilots are generally accepted as an improvement. Run it up to the rev limiter at full throttle. if it accelerates hard and then hits a wall, your mains are good. If it seems to run out of steam as it approaches the limit, you could try going up a little on the main I suspect 105 is a little too much, though.
 

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Discussion Starter #13
I don’t think I ever hit the rev limiter, at what rpm I’m supposed to hit it?
 

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Four shims IS a lot. But by your own testimony, it runs well. Is it using excessive fuel? Does it have other bad habits ? No complaints ? If it ain't broke don't fix it. You decide. ...J.D.
 

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Discussion Starter #17
Four shims IS a lot. But by your own testimony, it runs well. Is it using excessive fuel? Does it have other bad habits ? No complaints ? If it ain't broke don't fix it. You decide. ...J.D.
No other problems other than occasional stall on take off after idling for few minutes at a stop light.
I think I’ll assemble it the way it was and if I still have issues I’ll take two shims off at a time to see how it will effect it.
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Discussion Starter #19
As far as the float bowl seal goes, do you guys buy triumph or Kawasaki part? I think zrx1200 ones are the same
 

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I believe one would be as good as another
 
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